It is known that an access point device can be the coordinator, the center, and the initiator of an IEEE 802.15.4 based low power wireless personal area network (WPAN). However, due to the limitations of wireless protocols and the limited memory in access point devices, the number of wireless sensor devices connected to a single access point device is limited. For example, some known access point devices can be connected to 64 sensor device nodes or 128 sensor device nodes. In known RF6 WPANs, one access point device can support 128 sensor device nodes.
When known commercial wireless systems require and support hundreds or thousands of sensor devices, multiple access point devices are required to connect the sensor devices, and the multiple access point devices must also be connected to a control panel device in a corresponding wired or wireless manner. For example, as seen in FIG. 1, the access point devices AP1-AP8 can be connected to the control panel device 100 via a wired or wireless data bus 110, and each of the access point devices AP1-AP8 can coordinate a respective WPAN for connecting to a respective plurality of sensor devices. In known RF6 WPANs, the control panel device can support 1024 sensor device nodes by connecting eight access point devices. However, such configurations present a problem with the access point devices receiving signals from a portable device.
In known systems and methods that operate using an IEEE 802.15.4 protocol, a portable device, such as a RF6 key fob, can enroll with one of the access point devices. For example, the portable device can save in nonvolatile memory the network parameter of the one of the access point devices with which the portable device is enrolled, and the network parameter can include a specific channel identifier, a network identifier, such as a PANID, and an encryption key. When a user provides user input to a user interface device of the portable device, such as pressing a button on the portable device, the portable device can operate in the specific channel, receive the network identifier in a beacon signal from the one of the access point devices with which the portable device is enrolled, use the encryption key to decrypt a payload of the beacon signal, and responsive thereto, transmit a command signal to the one of the access point devices, which can transmit a corresponding command signal to the control panel device.
However, in known systems and methods, the portable device can only be enrolled with the one of the access point devices and cannot roam between the access point devices. For example, each of the access point devices operates in a respective one of a plurality of channels, and it is known that the portable device can traverse the plurality of channels and stay on each of the plurality of channels for a period of time, such as 500 milliseconds, to find the respective one of the channels on which the one of the plurality of access point devices with which the portable device is enrolled operates so that the portable device can receive the beacon signal from the one of the access point devices with which the portable device is enrolled. However, in such known systems and methods, the portable device might wait a long time to receive the beacon signal. Furthermore, the one of the access point devices may have a late response depending on when the user provides the user input to the portable device to initiate the portable device traversing the plurality of channels to receive the beacon signal. This results in a poor user experience.
In view of the above, there is a continuing, ongoing need for improved systems and methods.